It has been suggested that certain fluorocarbons which have commonly been used in refrigerants can damage the ozone layer when released into the atmosphere. This suggestion has led to the replacement of these damaging fluorocarbon refrigerants with non-ozone damaging fluorocarbons. As the ozone damaging fluorocarbons are removed and new non-damaging fluorocarbons are used, it becomes important to be able to identify and keep segregated the various types of refrigerants. Increased government regulation of the fluorocarbons in the United States adds to the responsibility of the refrigerant service facilities, such as automotive repair facilities, which handle refrigerants.
In the automotive field, refrigerants known as R12, R22, R134A and various hydrocarbon blends (such as OZ12 and OZ12A) have been used for automotive air conditioning refrigerants. Of these four refrigerants, R134A, OZ12, and OZ12A are the least ozone damaging refrigerants which are presently being used in automobiles. However, OZ12 and OZ12A can be explosive under certain conditions and are now considered undesirable for automotive refrigeration applications. Older cars may still be using R12 as a refrigerant. Because of the cost involved in converting existing automotive hardware to handle R134A, existing automobile owners may elect to continue using their prior refrigerant. Because of government regulation, however, R12 will no longer be manufactured after 1995.
R22 is a home air conditioning refrigerant which has been used, illegally, as a replacement for R12, because of its lower cost. R22 is not appropriate for use as an automobile refrigerant due to elastomer material incompatibility and higher vapor pressure of operation.
The various hydrocarbon blends are combustible and are no longer used as an automotive refrigerant.
It is possible in an automobile's refrigerant system, as well as in the storage tanks of a refrigerant service center or auto service center, that a mixing of the above refrigerants can take place. Because of the dangers associated with certain of the automotive refrigerants, as well as increasing government regulation regarding which refrigerants can be used, it is desirable to identify the individual refrigerant gases in both automotive systems and storage facilities in order to maintain separate and pure stores of these gases. If a storage tank of refrigerant gases is contaminated, it should not be used for refilling an automotive refrigerant system.
In commercial air conditioning/refrigeration installations, there are approximately 25-35 different commercial refrigerants which are commonly used. As in the case of the automotive refrigerants, certain commercial refrigerants are also ozone damaging. In addition, certain commercial refrigerants may be incompatible with a system designed for another commercial refrigerant. Because of the wide variety of refrigerants utilized in the field, it is possible that more than one refrigerant is inadvertently present in a particular commercial refrigeration system and/or refrigerant storage tank. Thus, it is desirable for commercial refrigerant systems to be able to identify all refrigerants present in the system.
Current products used for refrigerant identification have shortcomings and have not been met with a great deal of industry acceptance. Robinaire manufactures a device which uses thermal conductivity to measure R12 contained in R134A refrigerant supplies. This technology does not detect or account for air contained in the sample in its analysis. Carrier manufactures a device using chemical analysis, and is limited to detecting only a single refrigerant (R134A) and can not detect R22. Liebold Inficon uses acoustic technology and does not detect or account for air contained in the sample.
One method which has been used to identify gases is infrared spectroscopy. Most gases absorb infrared energy at specific wave lengths in the spectrum and, in many cases, at multiple points in the infrared spectrum. Infrared spectroscopy has been used to observe the phenomenon and identify particular gases. Traditional infrared spectroscopy equipment and methods, however, are not practical for field use at installations such as a local automotive repair facility because of cost, size, and robustness. Existing infrared spectroscopy units, designed for laboratory use, are inappropriate for rigorous "unclean" environments such as that found in a local automotive repair facility. They also fail to meet the requirements of a portable device for transport and operation at a particular commercial establishments having commercial refrigerant systems.
Tiff has manufactured a device using infrared analysis for detecting a single refrigerant, R12, using a single infrared detector. This device, too, does not detect and account for air which may be present in the sample. Accordingly, the accuracy for R12 analysis using the Tiff device is questionable if air is present in a sample.